CODEWITHSUNDEEP
javaregexregex-greedy
me.at.coding
me.at.coding

Reputation: 17654

Making + non-greedy?

Imagine I have the String

abcD

and I want to extract abc out of it. I thought of using

^(.+)D$

however then in matching group1, not only abc, but abcD is included - how to make the .+ less greedy, so D is not included in the group? I know I could use [^D]+, but is this really the only way?

Sorry, this was a reduced an bad test-case. Have a look at this sample (Java):

Pattern pattern = Pattern.compile("^(\\{(.+?)\\})?$");
Matcher matcher = pattern.matcher("{a}{b}");

System.out.println(matcher.matches()); // true

Why does this match? Shouldn't the regular expression just allow one { and one } in the String in total? I want only things like {< not } >} to match.

Upvotes: 0

Views: 165

Answers (2)

bonkydog
bonkydog

Reputation: 2032

"D" is not included in the first group, it is included in the full pattern match.

The first group is "abc".

You can see a demo of this at http://rubular.com/r/oSnF17Jd39

Upvotes: 0

Kenneth K.
Kenneth K.

Reputation: 3039

To make a quantifier less greedy, you add a ? after the quantifier:

^(.+?)D$

This depends, though, on your language or text editor. Different regex engines support different functionalities.

Upvotes: 2

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